An optical transmission module used in an optical communication system includes an optical modulator such as an electro-absorption modulator (EAM) or a Mach-Zehnder modulator (MZM), and a drive circuit for the optical modulator. A power density within the optical communication system has been increasing due to size reduction of the optical communication module such as an optical transmission module. A high power density makes it difficult to secure radiation of Joule heat generated by the optical communication module. Reducing power consumption of the drive circuit is a measure to suppress the generation of Joule heat. U.S. Pat. No. 7,519,301 discloses a drive circuit for outputting a driving signal via an emitter follower (EF) circuit. The drive circuit reduces the power consumption by controlling a current supplied by the current source of the emitter follower circuit in accordance with an input signal of the emitter follower circuit. However, a slow response of controlling the current source may decrease an amplitude of the output signal of the drive circuit and limit a modulation speed of the optical transmission module. A superior drive circuit which reduces power consumption thereof without degrading high-speed performance has been required for downsizing an optical communication module.